<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>书信系统 - 后台登录</title>
    <link rel="stylesheet" href="styles.css">
    <style>
        .admin-login-box {
            max-width: 400px;
            margin: 50px auto;
            background-color: #fff;
            padding: 30px;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        }
        .error-message {
            color: #e74c3c;
            margin-bottom: 15px;
            text-align: center;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="admin-login-box">
            <h1>后台管理系统</h1>
            <p>请输入管理员密码</p>
            <?php if (isset($_GET['error'])): ?>
                <div class="error-message"><?php echo $_GET['error']; ?></div>
            <?php endif; ?>
            <form action="admin_login.php" method="post">
                <input type="password" name="admin_password" placeholder="请输入密码" required>
                <button type="submit">登录</button>
            </form>
            <p class="converter-link"><a href="index.html">返回主页面</a></p>
        </div>
    </div>
    <script src="scripts.js"></script>
</body>
</html>